1. Field of Invention
The invention is related to welding. More particularly, the invention is related to a system and method for electroslag welding.
2. Description of Related Art
A typical highway and/or bridge includes a plurality of concrete sections that are spaced apart from one another to accommodate thermal expansion and contraction due to temperature changes. An expansion joint is inserted between the concrete sections to form a bridge between the concrete sections, thereby minimizing the irregularities on the surface of a highway. Thus, the expansion joint supports the dynamic traffic loads and accommodates the thermal expansion and contraction associated with bridges and/or highways. Additionally, the expansion joints can be configured to accommodate seismic loading.
Typically, the expansion joint includes a plurality of rails that are located between the concrete sections and are parallel to the edge of each concrete section. These expansion joint rails are parallel to one another and are evenly spaced apart from one another. The cross-section of the expansion joint rail varies depending on the expansion joint type. However, a gland cavity to hold the sealing element is required. Within the expansion joint, each of the flange faces of the expansion joint rail is substantially coplanar. A more detailed description of the expansion joint is provided in issued U.S. Pat. No. 4,923,328 titled “Maintainable Expansion Joint For Highways, Bridges and the Like” which is hereby incorporated by reference.
The expansion joint rails are supported by an advanced structure or a plurality of support beams which are tee-welded to the expansion joint rail. When support beams are used they are perpendicular to the expansion joint rails. Generally, the support beams are composed of the same parent materials as the expansion joint rails. During the process of fabricating the expansion joint, the expansion joint rails must be butt-welded together. The most common technique for butt-welding the expansion joint rails is to use flux cored arc welding techniques. Alternatively, shielded metal arc welding or submerged arc welding techniques may be used for butt-welding the expansion joint rails. Additionally, during the process of welding the expansion joint rails to the support beams, flux cored arc welding, shield metal welding or submerged arc welding techniques are used.
All the above mentioned welding techniques employ a multi-pass process for applying the weld metal to a weld cavity, which is time consuming. The number of man-hours required for butt-welding expansion joint rails is approximately 4 hours and for tee-welding the expansion joint rail to a support beam is approximately 2 hours. Therefore, it would be beneficial to provide a system and method for more efficiently butt-welding the expansion joint rails and tee-welding the expansion joint rails to the support beams.